A wideband dual-polarized horn feed with notch filtering function

Abstract

This invention discloses a broadband dual-polarized horn feed with notch filtering function, belonging to the fields of communication, measurement and control, and remote sensing reception. The ridges inside the four-ridge horn extend to the waveguide of the four-ridge horn. The four-ridge horn also contains two mutually perpendicular open-loop resonant ring structures; the first open-loop resonant ring is located on top of the second open-loop resonant ring. Each open-loop resonant ring structure mainly consists of a dielectric substrate and two open square rings. The dielectric substrate of the first open-loop resonant ring is positioned between two ridges in one plane, and the dielectric substrate of the second open-loop resonant ring is positioned between two ridges in another plane. Both open square rings are located on the same surface of the dielectric substrate, with one open square ring located within the area enclosed by the other open square ring, and their openings being far apart. This invention features a simple structure and flexible adjustable notch filtering frequencies for both polarizations. It meets the requirements for broadband feed suppressing spurious signal interference scenarios.

Description

Technical Field

[0001] This invention relates to the fields of communication, measurement and control and remote sensing reception, and in particular to a wideband dual-polarized horn feed with notch filtering function. Background Technology

[0002] The feed is a key component of a reflector antenna, and its performance directly affects the overall antenna performance. To detect a wider range of signals with varying strengths and frequencies, the feed antenna, as a core component, needs to have a wide bandwidth. This means the feed needs high illumination efficiency, stable radiation characteristics, a stable phase center, and a low reflection coefficient across a broad frequency band. Extensive research has been conducted by scholars both domestically and internationally to achieve wide-bandwidth feeds. Currently, the main implementations of wide-bandwidth feeds include Eleven Feed, ATA Feed, Sinuous Feed, and horn Feed. While Eleven Feed, ATA Feed, and Sinuous Feed can achieve wide bandwidth and relatively stable radiation characteristics within that bandwidth, feeding is difficult to implement because the feeding of the two arms requires a 180° phase difference. This necessitates additional components for balanced feeding, and maintaining a 180° phase difference between the two arms across the entire frequency band is challenging. Sinuous Feed can also achieve a wide bandwidth; however, the radiation pattern becomes asymmetrical with frequency variations, exhibiting an elliptical shape. In horn feeds, the corrugated horn is the most classic feed structure, possessing advantages such as rotationally symmetric radiation pattern and constant beamwidth within the frequency band. However, its structural characteristics limit its bandwidth ratio. By adding a gradually tapering ridge structure to a traditional horn, wideband characteristics can be achieved, and the ridged horn feed uses coaxial cable feeding, which is simple. Therefore, the ridged horn feed is widely used.

[0003] However, when a feedhorn operates over a wide bandwidth, it is more susceptible to interference from external signals. To address spurious signal interference in broadband feedhorns, a filter is typically added to the rear of the antenna to remove the interference. However, this approach leads to increased system size, structural complexity, and higher cost. Therefore, if the feedhorn itself has filtering capabilities, these problems can be avoided. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a broadband dual-polarized horn feed with notch filtering function. Two open resonant ring structures are loaded within the horn feed to suppress radiation at interference frequencies. This horn feed features a simple structure and flexible adjustable notch frequencies for both polarizations. It meets the requirements for broadband feed suppression of spurious signal interference scenarios.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A broadband dual-polarized horn feed with notch filtering function, wherein the four-ridged horn waveguide is connected to the input port of the four-ridged horn;

[0007] The bottom of the ridges inside the four-ridged horn extends into the waveguide of the four-ridged horn; the four-ridged horn also has two mutually perpendicular open resonant ring structures inside; wherein the first open resonant ring is located at the top of the second open resonant ring; each open resonant ring structure mainly consists of a dielectric substrate and two open square rings; the dielectric substrate of the first open resonant ring is positioned between two ridges in one plane, and the dielectric substrate of the second open resonant ring is positioned between two ridges in another plane; both open square rings are located on the same surface of the dielectric substrate, one of the open square rings is located within the area enclosed by the other open square ring and the openings of the two are far apart.

[0008] The four-ridged horn waveguide has a coaxial feed structure on one of its adjacent waveguide surfaces; the outer conductor of the coaxial feed structure is connected to the waveguide surface on which it is located, and its inner conductor is connected to the ridge on the opposite side.

[0009] Furthermore, the coaxially fed inner conductor passes through the waveguide surface and ridge on the same side, and is not in contact with either of them.

[0010] Furthermore, the coaxial feed structure is perpendicular to the waveguide surface in which it is located.

[0011] Furthermore, the open square ring can be replaced with an open circular ring.

[0012] Furthermore, the two open square rings located on the same dielectric plate are not in contact.

[0013] The beneficial effects of the above-mentioned technical solution adopted by the present invention are as follows:

[0014] 1. The notch characteristic method achieved by loading an open resonant ring structure in a broadband four-ridged horn feed does not increase the size of the system and reduces the complexity of the system structure.

[0015] 2. The frequency of its notch characteristics can be changed by adjusting the size of the open-circuit resonator.

[0016] 3. When the working environment of the horn feed changes, i.e. when the frequency of the interference signal changes, the change in the frequency of the interference signal can be addressed by flexibly replacing the open resonant ring structure of different sizes.

[0017] 4. The loaded open-loop resonant structure has little impact on the electromagnetic field distribution of the horn feed, ensuring good matching and radiation characteristics of the horn feed over a wide frequency band. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a cross-sectional view of a horn feed source with notch filtering function.

[0020] Figure 2 This is a top view of a horn feed source with notch filtering function.

[0021] Figure 3 This is a diagram of the overall structure of two open-loop resonant rings.

[0022] Figure 4 The results are simulation results of the VSWR of the horn feed voltage with an open resonant ring.

[0023] Figure 5 The results are simulations of the horn feed gain before and after loading the open-ended resonant ring. Detailed Implementation

[0024] In the following description, specific details such as particular device structures and techniques are set forth for illustrative purposes and not for limitation, so as to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0025] A broadband dual-polarized horn feed with notch filtering capability comprises a four-ridge horn, a four-ridge horn waveguide, a first coaxial feed structure, a second feed structure, a first slotted resonant ring, and a second slotted resonant ring. The four-ridge horn 1 is connected to the four-ridge waveguide 2. The inner conductors of the first coaxial feed structure 3 and the second feed structure 4 pass through the ridges and are connected to the ridges on their respective sides. The first slotted resonant ring structure 5 and the second slotted resonant ring structure 6 are embedded in the four-ridge horn feed, and the two slotted resonant ring structures are placed vertically to form notches at the interference frequencies for the two polarizations. Each of the two slotted resonant rings is composed of two square ring structures printed on a dielectric substrate. The slotted resonant rings 5 ​​and 6 are placed perpendicular to the magnetic field of their respective polarizations, ensuring that the slotted resonant rings exhibit notch characteristics. The notch frequency of the slotted resonant rings can be changed by adjusting their size. Furthermore, the two slotted resonant rings are the same size, ensuring that the two polarizations exhibit notch characteristics at the same frequency.

[0026] Furthermore, the two open-ended resonant rings can also adopt a circular structure.

[0027] Furthermore, the two open-ended resonant rings can have different sizes.

[0028] Furthermore, the notch filter frequency can be adjusted by changing the size of the resonant ring.

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0030] like Figure 1 , Figure 2 As shown, a broadband dual-polarized horn feed with notch filtering function includes a four-ridged horn 1, a four-ridged horn waveguide 2, a first coaxial feed structure 3, a second feed structure 4, a first open-circuit resonant ring 5, and a second open-circuit resonant ring 6. The dimensions of the stepped structure of the four-ridged waveguide section can adjust the matching performance of the feed structure. The ridge structure of the four-ridged horn adopts an exponential curve form to obtain good radiation performance. The four-ridged horn 1 is connected to the four-ridged waveguide 2. The inner conductors of the first coaxial feed structure 3 and the second feed structure 4 pass through the ridge plates and are connected to the ridge plates on their respective sides. The first open-circuit resonant ring structure 5 and the second open-circuit resonant ring structure 6 are embedded in the four-ridged horn feed, and the two open-circuit resonant ring structures are placed vertically, forming notches at the interference frequencies for the two polarizations.

[0031] like Figure 3 As shown, both split-ring resonators consist of two concentric square ring structures printed on a 6mm*6mm*1mm dielectric substrate. Split-ring 5 and split-ring 6 are placed perpendicular to the corresponding polarized magnetic fields, ensuring that the split-ring resonators exhibit notch characteristics. When an electromagnetic wave is incident on the split-ring resonator, the change in the magnetic field induces a current in the metal rings. Simultaneously, the current in the rings generates an equivalent inductance, and the accumulation of charge between the inner and outer rings generates an equivalent capacitance. Therefore, the split-ring resonator can be equivalently represented by an LC resonant circuit, and the notch frequency is... The notch frequency of a split-ring resonator can be changed by adjusting its size. Furthermore, having two split-ring resonators of the same size ensures that both polarizations exhibit notch characteristics at the same frequency.

[0032] Depend on Figure 4 It can be seen that both polarization ports of the horn feed with the open resonant ring form notches near 4.6 GHz, effectively eliminating signal interference in the 4.6 GHz band. Figure 5 Simulation results of the horn feed gain before and after loading the notch resonator are presented. As shown in the figure, after loading the notch resonator structure, the gain of both polarization ports of the horn feed is significantly reduced at the notch frequency, while the gain in other frequency bands remains basically unchanged. This ensures that the horn feed works normally except in the notch frequency band.

[0033] Brief working principle of the invention:

[0034] A broadband dual-polarized horn feed with notch filtering function comprises a four-ridge horn, a four-ridge horn waveguide, a first coaxial feed structure, a second feed structure, a first slotted resonant ring, and a second slotted resonant ring. The four-ridge horn is connected to the four-ridge waveguide. The inner conductors of the first coaxial feed structure and the second feed structure pass through the ridges and are connected to their respective opposite ridges. The first and second slotted resonant ring structures are embedded in the four-ridge horn feed, and the two slotted resonant ring structures are placed vertically, forming notches at the interference frequencies for two polarizations. Each of the two slotted resonant rings is composed of two square ring structures printed on a dielectric substrate. When an electromagnetic wave is incident on the slotted resonant ring, i.e., when the magnetic field changes, an induced current is generated on the metal ring. Simultaneously, the current on the ring generates an equivalent inductance, and the accumulation of charge between the inner and outer rings generates an equivalent capacitance. Therefore, the slotted resonant ring can be equivalently represented by an LC resonant circuit, and the notch frequency is determined accordingly. The first and second split-ring resonators are placed perpendicular to the magnetic fields of their respective polarizations, ensuring that the split-ring resonators exhibit notch characteristics. The notch frequency of the split-ring resonators can be changed by adjusting their dimensions. Furthermore, the two split-ring resonators are of the same size, ensuring that the two polarizations exhibit notch characteristics at the same frequency.

Claims

1. A broadband dual-polarized horn feed with notch filtering function, characterized in that, The four-ridged horn waveguide is connected to the input port of the four-ridged horn; The bottom of the ridges inside the four-ridged horn extends into the waveguide of the four-ridged horn; the four-ridged horn also has two mutually perpendicular open resonant ring structures inside; wherein the first open resonant ring is located at the top of the second open resonant ring; each open resonant ring structure mainly consists of a dielectric substrate and two open square rings; the dielectric substrate of the first open resonant ring is positioned between two ridges in one plane, and the dielectric substrate of the second open resonant ring is positioned between two ridges in another plane; both open square rings are located on the same surface of the dielectric substrate, one of the open square rings is located within the area enclosed by the other open square ring and the openings of the two are far apart. The four-ridged horn waveguide has a coaxial feed structure on one of its adjacent waveguide surfaces; the outer conductor of the coaxial feed structure is connected to the waveguide surface on which it is located, and its inner conductor is connected to the ridge on the opposite side.

2. A broadband dual-polarized horn feed with notch filtering function according to claim 1, characterized in that, The coaxially fed inner conductor passes through the waveguide surface and ridge on the same side, and is not in contact with either.

3. A broadband dual-polarized horn feed with notch filtering function according to claim 1, characterized in that, The coaxial feed structure is perpendicular to the waveguide surface it is located on.

4. A broadband dual-polarized horn feed with notch filtering function according to claim 1, characterized in that, The open square ring can be replaced with an open circular ring.

5. A broadband dual-polarized horn feed source with notch filtering function according to claim 1, characterized in that, The two open square rings located on the same medium plate are not in contact.

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